Conditions adjustment for in vivo mass production of a Colombian Spodoptera frugiperda nucleopolyhedrovirus

Abstract: The Colombian Spodoptera frugiperda nucleopolyhedrovirus isolate SfNPV003, was used for developing a biopesticide with great potential for the control of this pest in the field, becoming an alternative to replace chemical pesticides. However, its commercialization has been limited due to high costs for in vivo virus production, which have a significant impact on the product price. Traditional in vivo production involved feeding the virus to insect larva, temperature should be maintained carefully to keep the larva alive and to produce the highest yield and quality of virus, and larvae must be harvested at the proper time. In this sense, the aim of the present work was to adjust the conditions of SfNPV003 multiplication system, in order to increase yield and reduce costs. Initially, the effect of larval age and viral inoculum concentration on viral productivity was determined. Subsequently, the effect of diet for larvae rearing and incubation temperature was established. Finally, the effect of harvest time on productivity and contaminant content was evaluated. Sixteen days-old larvae were selected for inoculation with a viral suspension adjusted to a concentration of 1×107 occlusion bodies (OBs) per ml and wheat germ-based diet was selected for larvae rearing. Implementation of a temperature control system for incubation did not improve viral production. Seven days post- inoculation was selected as the optimum time for infected larvae harvest.